Cumene oxidation



.activity.

Patented Oct. 7, 1952 V H 1 .c TAI b i" Y George G; 'Joris'; Convent, N: JL, assignor to Aliied --Chemioal-.& Dye Corporation, New York, N. Y.,

acorporationothlew York 3.

' ."No Drawing, 'rptnca anmy 23, 1950;

"."SerialNo.1'63,805

' 4 Claims;v (Cl. 260-.610)

-This inventionrelates to liquidphase oxidation ability to cumene-hydroperoxide Each sample of cumene by elemental oxygen, particularly was oxidized by bubbling dried air therethrough oxygen of air, to produce cumene hydropero'xide in a. glass reaction vessel maintained at reaction as major product. l temperatures as specifiedbelow. The additives Oxidations by elemental oxygen of different 5 employed inthe examples-were in the form of cumene 'samplesin liquid phase are capable of suspensions of solid powdered additive in the reforming under identical experimental condiactionmixtures. a l tions varying proportions" of dimethyl phenyl Example 1.Three cumene samples were oxicarbinol, acetophenone, acids, degradation proddized'as outlined above at a temperature of 110 ucts, etc.-, as well as cumene h'ydroperoxide. C. in the presence of respectively soda ash Moreover, samples of commercial cumene give powder, Atomite (a commercial calcium carbowidely discordant results in terms of conversion nate powder) and barium carbonate powder adrates and yields for air oxidation of cumene to ditives, using 2 grams of each powder per-100 cc. cumene hydroperoxide. Additionally, cumene ofr'eaction mixture. In the table below, the reupon liquid phase oxidation with elementaloxysultsare summarized in terms'of rate of formagen exhibits an induction period, varying-with tio'n' ofcumene hydroperoxid'e at time intervals temperature and source and pretreatment of up to 7.5 hours (rates being-in weight percent the cumene, but observable-even'in the most concentration of cumene hydroperoxide formed readily oxidizable cumene" samples and even-at in thereaction mixture per hour during each relatively elevated temperatures, above 100 C. time-interval). l i it The foregoing facts are indicative of a chain It -will'be-sejen that except in presence of calmechanism foroxidation" of cumene to cumene 'ciumcarbonatecatalyst; even at this relatively hydroperoxide wherein-small amounts of foreign elevatedtemperature of 110 C. an induction materials may-exert inhibitor, catalyzer or cuperiod is evident, during which cumene oxidamene hydroperoxide decomposition accelerator tion is initially slow. Yields of cumene hydror peroxide based on 'reactedcumeneare substan- An object of this invention is to provide a tiallythe same for all the additives and are in :specific additive which; when present even in the-vicinity of'94% of theory at the final concencatalytic quantitiesp greatly diminishes the "tra'tion reached. When -no additive is employed irregularities normallypb'ser-ved in cumene oxi- 3 the yieldsand rates under the above conditions dations and 'moreover shows specific catalytic are much lower than those of the table.

activity, increasing oxidation rate over those 1 obtainable with-*noadditive and resulting in improved yields of cumene hydroperoxde based on I lntervalhlmm's cumene reacted, as against yields in absence of an additive. I

Nalool CaCOa B3003 Rate R ate Rate In accordance with my invention, I contact cumene during oxidation thereof inliquid phase by elemental oxygen with solid calcium carboe nate, suitably in suspension as a powder in the 40 i Oxidation reaction r I .Edidmple 2.The efiect'of calcium carbonate in Calcium. Frbonate i dlstmguished yflrom r eliminating induction periods at lower operating lated mammals. a i m c na ean temperatures i's'illustrated by the following exbarium carbonate, in e t 0 a oni ample} Acumene sample'was' oxidized as above, cumene by the fact that solid calcium carbonate exceptthat 1 gram of At t calcium carbonate additive eliminates the induction period norpowder per 1 cm f reaction mixture and a many Observedin cumene Oxidation temperature of C. were employed. The re- Small amounts of calcium carbonate are operan may be Summarized as follows; tive in my process. For example, amounts as small as 0.1 gram per cc. of reaction mix- 50 ture exert beneficial influence on the oxidation cumene ydr id 0 reaction. Larger amounts, up to about 5 grams Time, hours t iim in 1 1 3?- of calcium carbonate powder per 100 cc. of re- 7 tion Mixt re action mixture produce still better results and (WgtPement) still larger quantities may be used but offer no 3.25 particular advantage. 15.25

The following examples are illustrative of my 22 $2 invention, but it is not intended that the inven- '26 tion be limited thereto. The cumene samples 31 employed in these examples were of high oxidiz- When 2 grams'of the calcium carbcnatepowder per 100 cc. of reaction mixture,.instead of 1 gram per 100 00.. were employed in the procedure of this example a faster reaction resulted, in

which there was likewise no induction period and which produced a 35.5% cumene hydrop'eroxide concentration in 41.5 hours. The-yields of hydroperoxide based on reactedcumene in these: two

runs, at the final hydroperoxide concentrations reached, were respectively 93% and 92% as measured iodometrically (a method which usually gives somewhat low results).

The oxidation is practically free of -an induction period at 90 C. when carried out as above but with only 0.5 gram of: the calcium carbonate powder per 100. cc. of.-reactionmix ture; but has correspondingly lower rate; going tov about 25% hydrop'eroxide. concentration-fin 44 hours with 94% yield,and thereafter falling off in rate and yield. With smaller amounts of the powder, marked advantage-inoverallrate and yield as comparedto. noadditive is.- still obtained, but inductionperiods'appear. Larger amounts of powder than 2 gramper 1()0 cc.,=e. g. 5 gram per 100 cc. have been usedsuccessfully but without advantage over use of 2- gm. per

Resultsobtained vary somewhatwith the source and preparation method of the: calcium carbonate powder, but all calcium.carbonate powders tested have given beneficial results of the character above-described. 3 I

An advantage of calcium carbonate. additive is that oxidation of cumene using this additive is substantially unaffected by presence or absence of water'in the. reactionsmixture; accordingly precautions need not' be taken. to.- exclude water during the oxidation; nor need i water be present.

Calcium carbonate additive may. be used simultaneously with one or.-more. other. additives, e. g. soda ash. Ratesof oxidation in-presence of calcium carbonate alone maytend to drop after about a -35% cumene hydroperoxide concentration has been attained. Presence-of soda ash overcomes this tendency, as shown by the following example.

Example 3.Four cumene samples were oxidized at 90 C. as inExample2 above, each in presence of 2 grams of solid powder per 100 cc. of reaction mixture. These powders were respectively calcium carbonate as used above, and 3:1, 2:2 and 1:3 weight ratio mixturesof the calcium carbonate with soda ash powder. All four oxidation reactions showed about the same rates up to about 25% cumene hydroperoxide concentration, but when calcium carbonate powder alone was used, oxidation rates dropped off at. about 25% cumene hydroperoxideand dropped sharply at about 35% cumene hydroperoxide concentration, with yields also declining. In the three runs with mixed powders,

however, the oxidation rate stayed about constant throughout each of the three runs, all of which reached 41-43% cumene hydroperoxide concentrations after 46-48 hours. The yields of. hydroperoxide throughout these runs with mixed powders were very good being at least 92% of theory at the end of each (iodometric method of analysis) advantage of calcium carbonate over certain other additives is that in its presence, temperatures above C. can be used for cumene oxidation with corresponding high oxidation rates and-with obtainmentof' good yields. This is: illustrated in- Example 1 above whichshows using a temperature of C. and obtaining. a rate of 2% per hour of cumene hydroperoxide formation with'yield of about 94% of theory at 15-16%- cumenehydroperoxide concentration. With calcium carbonate additive, temperatures ashigh as: C. or even- C. can be employedatleast briefly; and temperatures. as low as 70- C. give appreciable oxidation rates. Preferred cumene oxidation temperatures inpresence of calcium carbonate-- are inthe range {ED -110 G. and more especially. 90'-110 C. as shown in the above examples.

1; Theimprovementin processes for oxidizing cumene in liquid phase by elemental oxygen to cumene hydroperoxidewhich comprises. contacting said cumene with solid calcium carbonate during said oxidation.

2. Processas definedwin claim-1 ,.wlierein oxidation is effected at-temperaturesin-the range 90 -110 C. and air is employedas oxidizing agent; I

3. Process as defined in claim 2, wherein sodiumcarbonate powder is present along with calcium carbonate powder.

4. Process-as defined in claim.1,.wherei'n at least. about 0.1 gram -of-- calcium carbonate powder: per 100 cc. of reaction-mixture is employed and temperatures during. at least part of' the oxidation-periodare above 100 C.-

v v encased; some.

REFERENCES CITED The 1 following: refeiences are: of record in: the file of this patent:

UNITED STATES PATENTS 231M341 Lorand Oct. 18. 1949 

1. THE IMPROVEMENT IN PROCESSES FOR OXIDIZING CUMENE IN LIQUID PHASE BY ELEMENTAL OXYGEN TO CUMENE HYDROPEROXIDE WHICH COMPRISES CONTACTING SAID CUMENE WITH SOLID CALCIUM CARBONATE DURING SAID OXIDATION. 